Question
Rose leaves with spots
I'm new to roses but love their color and scent. About two weeks ago, I purchased a J&P Double Delight hybrid tea rose in a two gallon container. After a little initial stress (I put it in full sun, but judging from its response, it had never actually been outside of a greenhouse) its perked up pretty well. A couple days ago, I noticed these blackish/purple spots on many of the leaves. I assume that it is some variety of rose disease but can't find any applicable web photos and don't really have the confidence to diagnose it myself. What has caused these spots and what do I do about them? Thank you.
Note: The white on the leaves in the pictures is not (I don't think) related to the spots, its just a little residue from the insectide I sprayed them with yesterday.
AnswerMany roses get a fungal diseases when the weather conditions are right for it. Your particular problem is called downy mildew. You can try to spray it daily with a mixture of 1 tablespoon of baking soda in 2 quarts of water and see if that cleans the leaves up. If the fungus has taken a stronger hold and won't go away with the baking soda spray, then Orthos Rosepride Funginex Rose and Shrub Disease Control spray will solve the problem. Just follow the instructions on the label. The fungal spores float around in the air and are pushed to the ground by either wind or rain. When they land on a rose leaf they start their life cycle.
